1. Field of the Invention
The present invention relates generally to satellite communications and, more particularly, to estimating beacon power variations in satellite communications.
2. Description of Related Art
In satellite communications, a satellite periodically transmits a beacon signal to earth-based satellite terminals. The beacon signals may be used by the satellite terminals in establishing communications with the satellite. Each satellite terminal may also determine the carrier-to-noise (C/N) ratio of the beacon signal for use in downlink power control (DLPC) related processing.
One problem with using the C/N ratio of the beacon signal in DLPC related processing is that the beacon power (e.g., the effective isotropic radiated power (EIRP)) may vary during the course of each day and may also vary over time (i.e., with the age of the satellite). In such a case, the variation in beacon power may be considered to be noise, the result of rain or some other problem. These variations in beacon power may adversely impact the DLPC related processing. For example, in some systems, beacon power variations may result in determining that the satellite must increase power levels for transmissions to one or more cells. Such increases in transmission power levels may reduce the efficiency associated with managing the satellite's power resources and may lead to availability reductions in situations which require efficient control of the satellite's power resources.
Therefore, a need exists for systems and methods that estimate beacon power variations and adequately compensate for these variations.